Rotary pressure or vacuum pump.



W. C. CUTLER.

. ROTARY PRESSURE 0R VACUUM PUMP.

APPLICATION FILED JULY 10,1913.

1 188 73? Patented June 27,1916.

WILLIAM CLIFTON CUTLER, F SAWTELLE, CALIFQRNIA, ASSIGNOR T0 LEONARIQROTARY PUBIP CORPORATION, A CORPORATION 01: CALIFOENIA,

RQTARY PRESSURE 0E VACUUM PO'hl'li'.

wearer.

specification of Letters Eatent.

gases and the object of'the invention is to provide a rotary pressure orvacuum pump by means of which a far greater pressure or vacuum may beproduced than heretofore by any known rotary pump.

A further object is to prevent internal leakage in the pump.

A further object of the invention is to eliminate all valves and toattain eficiency ,of operation, simplicity and economy of con-'struction and entire absence of reciprocating parts.

In carrying out my invention, I employ a pair of gears which mesh witheach I other and rotate in opposite directions,-the gears being.confined in a casing with an admission at one side and an exhaust at theOiIhGL: lhe gears fit with a close working fit within the casing andwhen employed as a pump for gases or vacuum, are submerged in somelubricating liquid which not only acts as a seal to prevent any backleakage from the exhaust side to the inlet side; but, thoroughlylubricates all working parts. When used as a liquid pump the liquidforms its own seal.

Referring to the drawings: Figure 1 is a vertical cross section throughthe device.

Fig. 2 is a section on line A. Fig. 3 shows the form of ar used.

In its pre erred form the invention consists of a casin 1 within whichare two gears meshing with each other and mounted on shafts 3 and 4which are journaled in the sides of the casing l. The casin fits thegears only about one half their circumference, leaving the upper portionof the gears in contact with the sealing fluid 5.

6 is the inlet port connecting on outside of pump with pipe 7 and someform of check valve 8 to prevent the liquid from leaking out when pumpis not running.

exhaust port is provided at 9 and a bafile plate is mounted at 10. Theshaft 3 extends through a'stufing box 11 and carries a within said case,the gears having sprocket wheel or pulley at 12. The casing is in twoparts and bolts together at line 13.

In operation the gears are rotated in the direction of the arrow whichproduces a suction through pipe 7 on account of the teeth of the gearsremoving all gas or liquid from space 14 and carrying itcircumferentially around with the gears where it discharges into theliquid through which it rises to the space 15 and finally passes out ofexhaust port 16.

As the gears rotate and their teeth close together, a certain amount ofliquid will be trapped next the bottom of each tooth; this liquld cannotescape as rapidly as it is necessary to rotate the gears thereby settingup an outward or pressing apart strain on the gears and bearings,causing them to run hard and necessitating a lossof power. In order toobviate this diiiiculty, I dispose the teeth of the gears obliquely,forming what are called herringbone gears Fig. 3,

but so placing them that as the teeth come together the center angle Ain the gears is the last part of the tooth to'strike, thus graduallyrunnln any entrapped liquid from the side casing inwardly toward thecenter of the ears, where the final small amount of liquid is dischargedat the relief opening shown at B, Fig. 3, which is a cut taken out ofthe face of the tooth and extendingdownwa rdly toward its base. Thisrelief openin is ofgreat importance as it almost entire y relieves alloutward strains due to the imprisoned liquid even under speeds runningover 1000 revolutions per minute.

Where the gears are disposed horizontally, a splash plate is mounted at10 to prevent the liquid under the speed of the gears from being thrownthrough the exhaust port'9, where the pump is to be operated as an airpressure or exhaust pump. When used as a liquid pump, the splash platecan be dispensed with. With this form of pump and gears, the inventorhas at 7 revolutions per minute, attained a pressure exceeding 185pounds per square inch in a single stage compressor.

What I claim is:

1. A rotary air or liquid pump comprising a case with inlet and outletports; a pair of intermeshing gears rotatively mounted teeth PatentedJune 2?, 191%.,

obliquely disposed with the vertex of their are angle at their lastpoint of contact; a relief o ening cut from the face of the tooth at t evertex of their angle and extending I the teeth of said gears obliquelydisposed downward toward the base of the tooth. 2. A rotary air orliquld pum comprismg a case in which are mounte a Pfi-IFOIE intermeshinggears; an intake port in the case at one side of the gears; an exhaustport in the case at the opposite side of the gears; the teeth of saidgears obliquely disosed, forming an angle at the center of the ace ofthe gears at' the point of last contact; a relie opening out from theface of the gears at the vertex of their angle and extending toward thebase of the tooth.

3. A rotary air or liquid pump comprising a casein which are mounted apair of intermeshing gears; an intake port in the case at one side ofthe gears; an exhaust port in the case at the opposite side of thegears;

forming an angle at the center of the face of the gears at the point oflast contact; a relief opening cut from the face of the gears at thevertex of their angle and extending toward the base of the tooth; aliquid seal covering said gears;

In testimony whereof, I have hereunto set my hand at Los Angeles,California, this 12th day of A ril, 1913.

' WILL AM CLIFTON CUTLER. In presence of- A. F. TRIPPELL, E. A. HIeers'.

